Youji Sakiyama
The protagonist of the series. Youji is a high school student who lives by himself in a small flat, attending a private and devote Christian academy. His parents died in a car accident when he was a kid, leaving him and his older sister with no other relatives. Youji suffers from a weak body due to the accident, and has bad health throughout most of the visual novel. Because of his health condition, he misses school numerous times and ultimately had to repeat a year, alienating him from most of his classmates. Youji is shy and aloof, silent more often than not. He finds making conversation difficult and enjoys his solitude. It is later revealed by Kamiya that Youji is not human, but rather a "mesu." Likewise, Shironuma Testuo (a man who is a year younger than Youji but in the same class) is revealed to be the perfect "osu." Both are attracted to each others pheromones, and within the visual novel, the only "good ends" that occur are the ends between Testuo and Youji.